/*
 * Copyright (c) 2011-2025 PiChen
 */

package com.interface21.web.servlet.theme;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.interface21.web.util.WebUtils;
import com.interface21.web.servlet.support.RequestContext;

/**
 * Implementation of ThemeResolver that uses a cookie sent back to the user
 * in case of a custom setting, with a fallback to the fixed locale.
 * This is especially useful for stateless applications without user sessions.
 * <p>
 * <p>Custom controllers can thus override the user's theme by calling setTheme,
 * e.g. responding to a certain theme change request.
 *
 * @author Jean-Pierre Pawlak
 * @author Juergen Hoeller
 * @since 17.06.2003
 */
public class CookieThemeResolver extends AbstractThemeResolver {

    /**
     * Name of the request attribute that holds the theme name. Only used
     * for overriding a cookie value if the theme has been changed in the
     * course of the current request! Use RequestContext.getTheme() to
     * retrieve the current theme in controllers or views.
     *
     * @see RequestContext#getTheme
     */
    public static final String THEME_REQUEST_ATTRIBUTE_NAME = CookieThemeResolver.class.getName() + ".THEME";

    public static final String DEFAULT_COOKIE_NAME = CookieThemeResolver.class.getName() + ".THEME";

    public static final String DEFAULT_COOKIE_PATH = "/";

    public static final int DEFAULT_COOKIE_MAX_AGE = Integer.MAX_VALUE;

    private String cookieName = DEFAULT_COOKIE_NAME;

    private int cookieMaxAge = DEFAULT_COOKIE_MAX_AGE;

    private String cookiePath = DEFAULT_COOKIE_PATH;

    /**
     * Use the given name for theme cookies, containing the theme name.
     */
    public void setCookieName(String cookieName) {
        this.cookieName = cookieName;
    }

    public String getCookieName() {
        return cookieName;
    }

    /**
     * Use the given path for theme cookies.
     * The cookie is only visible for URLs in the path and below.
     */
    public String getCookiePath() {
        return cookiePath;
    }

    public void setCookiePath(String cookiePath) {
        this.cookiePath = cookiePath;
    }

    /**
     * Use the given maximum age, specified in seconds, for locale cookies.
     * Useful special value: -1 ... not persistent, deleted when client shuts down
     */
    public void setCookieMaxAge(int cookieMaxAge) {
        this.cookieMaxAge = cookieMaxAge;
    }

    public int getCookieMaxAge() {
        return cookieMaxAge;
    }

    public String resolveThemeName(HttpServletRequest request) {
        // check theme for preparsed resp. preset theme
        String theme = (String) request.getAttribute(THEME_REQUEST_ATTRIBUTE_NAME);
        if (theme != null)
            return theme;

        // retrieve cookie value
        Cookie cookie = WebUtils.getCookie(request, getCookieName());

        if (cookie != null) {
            return cookie.getValue();
        }

        // fallback
        return getDefaultThemeName();
    }

    public void setThemeName(HttpServletRequest request, HttpServletResponse response, String themeName) {
        Cookie cookie = null;
        if (themeName != null) {
            // set request attribute and add cookie
            request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME, themeName);
            cookie = new Cookie(getCookieName(), themeName);
            cookie.setMaxAge(getCookieMaxAge());
            cookie.setPath(cookiePath);
        } else {
            // set request attribute to fallback theme and remove cookie
            request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME, getDefaultThemeName());
            cookie = new Cookie(getCookieName(), "");
            cookie.setMaxAge(0);
            cookie.setPath(cookiePath);
        }
        response.addCookie(cookie);
    }

}
